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Diffstat (limited to 'arch/x86/include/asm/spinlock.h')
-rw-r--r-- | arch/x86/include/asm/spinlock.h | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h new file mode 100644 index 000000000..5b6bc7016 --- /dev/null +++ b/arch/x86/include/asm/spinlock.h @@ -0,0 +1,45 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_SPINLOCK_H +#define _ASM_X86_SPINLOCK_H + +#include <linux/jump_label.h> +#include <linux/atomic.h> +#include <asm/page.h> +#include <asm/processor.h> +#include <linux/compiler.h> +#include <asm/paravirt.h> +#include <asm/bitops.h> + +/* + * Your basic SMP spinlocks, allowing only a single CPU anywhere + * + * Simple spin lock operations. There are two variants, one clears IRQ's + * on the local processor, one does not. + * + * These are fair FIFO ticket locks, which support up to 2^16 CPUs. + * + * (the type definitions are in asm/spinlock_types.h) + */ + +/* How long a lock should spin before we consider blocking */ +#define SPIN_THRESHOLD (1 << 15) + +#include <asm/qspinlock.h> + +/* + * Read-write spinlocks, allowing multiple readers + * but only one writer. + * + * NOTE! it is quite common to have readers in interrupts + * but no interrupt writers. For those circumstances we + * can "mix" irq-safe locks - any writer needs to get a + * irq-safe write-lock, but readers can get non-irqsafe + * read-locks. + * + * On x86, we implement read-write locks using the generic qrwlock with + * x86 specific optimization. + */ + +#include <asm/qrwlock.h> + +#endif /* _ASM_X86_SPINLOCK_H */ |